I am just trying player 11.1 on linux (before I was using 10.0) and was quite disappointed that the new player no longer stops at an exception but just writes it to the log file.

Is there any way to configure this behaviour?

Another one: I sort of understand that Adobe fixed the name of the log file to prevent evil natures from pointing the mm.cfg file at weird places. However, both the old and the new way do not really help if you are trying to debug two separate flash applications, each one running in standalone player and writing to the log. Is there any way around?

for the first point: you say that player 11 just catches unhandled exceptions (those that used to popup a window with a stack trace and pause execution) and writes the message to tracelog. So I could probably add my own handler instead. Is there a simple way to get the full stack trace from user code? Is there a way to pause execution?

I am asking about pausing, because I recall a situation where the same swf with a bug inside enterframe code running on linux would just show the error, while running inside flash professional I really had to cycle power ... 3 fingers would show the windows page that leads to task manager, but the next error event would put the flash window in the foreground

logging: I used this approach a couple of years ago - it was the only way to get debug messages from a browser in linux at that time. The downsides of this approach: a) output would end in a window rather than in a file. b) I could not use trace() but rather had to call a function of my own. Today, I feel that a) would need a process that dumps received data to a server script, but how about b) I recall somebody was talking about preloading code. Would it be possible to override global function trace() this way?

Maybe I wasn’t clear. FP 10.0 did not support the UncaughtErrorEvent and related APIs. FP 10.1 and later do. If a SWF is using UncaughtErrorEvent APIs it might throw an error on 10.1 and not on 11. FP 11 (at least on other platforms still shows the error dialog).

You can try using UncaughtErrorEvent to see if you can catch the error and report it via trace or some other mechanism. I don’t know of any way to replace trace().